1. Field of Invention
The present invention relates to Reverse-Rotation Displays, and, more particularly, to Reverse-Rotation Displays that produce variable rotational speeds.
2. Prior Art
There is something very special about how the eyes and the brain perceive moving objects. Things that move always captivate us; they demand our attention. That's easy to see by watching a cat play with a ball. Motion, of all kinds, is used in a wide range of activities. However, the motion of interest here is rotational motion for education and certain other uses. Rotational motion, typically, has the advantage of being able to accomplish specific objectives in a limited space. Examples are easily seen in store windows where rotating displays are common.
U.S. Pat. No. 3,919,795 to Jinivisian et al. (1975) describes a motorized mobile for use over a child's bed or crib. That patent includes a motor for driving a mobile. The direction of rotation is determined by the construction of the mobile. Operation in the reverse direction is not possible.
U.S. Pat. No. 5,232,105 to Gregg (1993), and U.S. Pat. No. 6,250,798 to Brainard et al. (2001), use motors to rotate crystals to redirect sunlight within a room. These displays are used to entertain, or for aesthetic purposes. In both cases, the crystals always move in the direction that the motor turns. There are at least two ways to overcome this limitation; both would make the displays more expensive. First, provide the added feature that would allow the motor to reverse direction at regular intervals. Second, add a second display: one to rotate the crystals clockwise; one to rotate them counterclockwise. Its likely neither would be pragmatic.
Two U.S. patents issued to French, U.S. Pat. No. 6,853,283 (2005), and U.S. Pat. No. 6,937,125 (2005), involve self-powered spherical displays. Those patents show two concentric hollow spheres separated by a transparent fluid. The spheres define the inventions. The only external force tolerated by the inner sphere is a magnetic force. Mechanical contact, from outside the two concentric spheres, to the inner sphere, would throw the “self-powered moving display” into disorder. For example, if the inner sphere of one display was mechanically coupled to the inner sphere of another display, neither display would function.
Please Note: The term Display(s) is used throughout this application to mean Reverse-Rotation Display(s).